People suffering from diabetes should preferably perform periodic measurement on his/her blood glucose level so that appropriate prescription or other treatments can be arranged in response to the measuring results. A conventional example of a measuring instrument for this purpose is disclosed in JP-A 8-262026.
As shown in FIG. 19, this conventional instrument includes a casing 90 having an upper surface provided with a control 91, upon operation of which part of a sensor S projects out of an opening 90a from a tip of the casing 90. The sensor S is a small piece containing a reagent which reacts with glucose in the blood. When the sensor S makes contact with the blood of the user, a measurement circuit (not illustrated) in the casing 90 measures a glucose level in the blood, and a result of the measurement is displayed in a display 92.
The casing 90 accommodates a cartridge or a package 95 as shown in FIG. 20. The package 95 includes a package substrate 95a having a plurality of radial recesses 96 each holding a sensor S, and a film 95b covering an upper surface of the package substrate 95a. The package 95 is rotatable when attached in the casing 90, and the rotating action changes positions of the sensors S. In conventional measuring instruments, the film 95b of the package 95 is partially cut with an appropriate blade for example, and then the sensors S are pushed through this cutout by a predetermined pusher, sequentially one after another toward the opening 90a of the casing 90.
According to such a construction, it is possible to use each of the sensors S in the package 95, sequentially one at a time after another, and to perform a plurality of measurements of the blood glucose level.
However, according to the conventional art, it is not possible to easily refill as many sensors S as needed into the package 95 when the sensors S in the package 95 are running short. Therefore, it is not easy to always have the measuring instrument loaded with a sufficient number of sensors beyond a certain quantity. This is inconvenient. In order to load the measuring instrument with the sensors S, replacement must be made with a whole new package 95, and a lot of sensors S would be wasted if the replacement is made with a whole new package while the current package 95 still has unused sensors S.